The Indian Chief Dark Horse uses 9003 bulb size for both high beam and low beam headlight applications. Replacement chart data covers 2010 to 2018 model years with corresponding bulb size specifications.
The year-by-year compatibility chart below provides a quick reference to verify the correct bulb size for your vehicle.
The 9003 is a dual-filament halogen bulb, meaning a single unit contains separate filaments for both high and low beam functions. It operates at 12 volts and draws 60 watts on the high beam filament and 55 watts on the low beam filament.
The 9003 uses a P43t base, which is a three-tab bayonet-style mount. This base type is standardized under ANSI specifications applicable in the United States and Canada.
The Indian Chief Dark Horse uses the 9003 bulb for both the high beam and low beam headlight positions across the 2010-2013 and 2016-2018 model years covered in the specifications.
Because the 9003 serves both beam positions on this motorcycle, a single bulb type covers the full headlight assembly rather than requiring separate part numbers for each function.
The 9003 is functionally interchangeable with the H4 bulb, as both share the same dual-filament design and P43t base. The 9003 designation is the ANSI standard used in North America, while H4 is the ECE designation used elsewhere.
The wattage difference between the two filaments, 60W for high beam and 55W for low beam, reflects the higher luminous output required for the high beam function relative to the low beam.